Slurry handling pump

ABSTRACT

A SLURRY HANDLING PUMP INCLUDING A SCROOL CASING AND A CENTRIFUGRAL IMPELLER HAVING ANGULARLY SPACED BLADES WITH THEIR INNER EDGES BEING RADIALLY SPACED FROM THE AXIS OF ROTATION OF THE IMPELLER. PORTIONS OF THE FREE ENDS OF THE BLADES TOWARDS THE AXIS OF ROTATION EXTEND OUTWARDLY OF THE PUMP INLET. THE PUMP INLET INCLUDES A PAIR OF SLOTS EXTENDING RADIALLY FROM THE EDGE THEREOF.

l971 NlLS-JOHAN SAHLSTROM 3,560,105

I swam: HANDLING PUMP Filed Feb. 13, 1969 I i i 'l INVENTOR Nils JohanSuhlstrom United States Patent Office 3,560,106 Patented Feb. 2, 19713,560,106 SLURRY HANDLING PUMP Nils-Johan Sahlstrom, SahlstromManufacturing Co., N-J Sahlstrom Maskin AB, Suntetorp, Skovde, SwedenFiled Feb. 13, 1969, Ser. No. 799,017 Int. Cl. F01d 1 02, 25/24; F04d7/00 US. Cl. 415-204 6 Claims ABSTRACT OF THE DISCLOSURE This inventionrelates to a slurry handling pump, and particularly to a centrifugalpump particularly adapted to handle barnyard or stable manure stored ina tank, or the like.

An earlier invention of mine relates to apparatus for handling barnyardor stable manure, which invention includes a slurry receiving tank andpumping means disposed in the tank. My pumping means, both of this andthe earlier invention, has a dual function, one is to act on the solidmatter to break it up and blend it with the liquid constituent to form aslurry, and the other is to pump the slurry out of the tank. My pump inmy earlier invention, as well as in the present invention, is preferablya centrifugal pump having a scroll casing with a tangential dischargeopening and an inlet opening generally coaxial with the axis of rotationof the pump impeller.

One problem in the blending of manure into a slurry, is that of cloggingof the pump inlet by mats of straw, large masses of manure, or the like.In my earlier invention I used fixed vanes across the pump inlet forbreaking up any masses of material before they could bridge the inlet toclog it. Although these vanes do an adequate job in breaking up themasses of material, there are times when one or more sectors definedbetween the vanes become clogged.

Another problem in handling slurry is that occasionally solidunbreakable objects, such as stones, for example, are deposited in thestorage tank. These solid objects will be drawn into the pump andsomtimes will jam the pump resulting in shear pin failure.

The pump of my present invention overcomes the problem mentioned above,as well as other. As to the clogging problem, portions of the free endsof the blades of my pump extend beyond the inlet opening of the casing,and any large mass of material at the inlet will be struck by the bladesand broken apart. Thus, I eliminate the need of mounting fixed vanesacross my inlet. In addition, I find that I can break up masses ofmaterial very efficiently with the extended blade portions. I alsoarrange my bades so that their inner radial edges are not mounted on ahub, but, rather, are radially spaced from the axis of rotation of thepump impeller. In essence, I provide a blade arrangement which has acentral pocket, so to speak. Stones or other unbreakable matter, willenter this pocket area and then get thrown radially into the casing andout the discharge opening to thereby avoid any jamming of the impeller.One other problem is avoided by my hubless blade arrangement, that beingthe wrapping of fibrous material, such as straw, rope, or the like,around a hub.

I also provide, in my preferred embodiment, improved means for severingfibrous material, such as straw or rope. My inlet opening is preferablyprovided with radially extending slots so that the centrifugal forceimparted to fibrous material will urge it into the slots. My blades moveover the inner surface of the casing and pass over the slots to therebyshear the fibrous material and throw the top piece radially into thecasing to be discharged.

More specifically, my invention preferably comprises: a hollow scrollcasing having an axial inlet opening means at one end thereof, and atangential discharge opening means through the side wall thereof; andcentrifugal impeller means supported by the casing for rotation relativethereto; the impeller means including a disc shaped base member disposedadjacent the other end of the casing, a plurality of axially extendingangularly spaced blades, each of which blades having one end fixed tothe base member and the opposite end having a first portion extendingoutwardly beyond the inlet opening and a second portion within thecasing and adjacent the inner surface of the said one end of the casing.

Other details and advantages of my invention will become apparent as thefollowing description thereof proceeds.

In the accompanying drawings, I have illustrated a present preferredembodiment of my invention in which:

FIG. 1 is a side elevation view partly in section of a slurry handlingpump embodying my invention; and

FIG. 2 is a view looking into the inlet opening of the pump of FIG. 1,with a part of the casing broken away to show a detail of construction.

Referring to the drawings, 1 generally represents the slurry handlingpump of my invention. Pump 1 would be placed in a storage or receivingtank into which barnyard or stable manure, urine, straw, and the likewould be placed. My pump 11 would be arranged in the vicinity of thebottom of the tank. A typical arrangement of my pump 1 disposed in atank together with auxiliary equipment is shown and described in my US.Pat. 3,263,968 for Slurry Handling Apparatus.

Pump 1 includes a typical scroll shaped casing associated withcentrifugal pumps. An impeller assembly is supported by the casing forrotation with respect thereto. The casing is provided with inlet openingmeans 4 arranged generally coaxially with the axis of rotation of theimpeller assembly. The casing is also provided with a tangentialdischarge opening 2 through the side wall of the casing.

The inlet opening means 4 is provided by a plate member 3 removablyfixed to one end, ie, the lower end for clarity of description, of thecasing as by threaded bolts, for example. The plate member 3 is fiat andgenerally circular in shape, with the inner surface thereof beinggenerally flush with the adjacent inner surface of the lower end of thecasing. The inlet opening is, as mentioned earlier, generally coaxialwith the axis of rotation of the impeller assembly. The inlet openingmeans 4 is also provided with a pair of diametrically opposed slots 9extending generally radially outwardly with respect to the edge of theinlet opening. Each slot 9 is formed in a generally V-shape having oneside 10 generally tangential to the circle defined by the inlet opening,and the other side 11 being generally along a radial line of the samecircle. Thus, any fibrous material, such as straw, rope, or the like,carried around the edge of the inlet opening by the impeller bladeswill, by virtue of the centrifugal force imparted to it, move along theside 10 of slot 9 and lodge itself therein. The reason for providing theslots 9 for lodging fibrous material will become apparent as thisdescription proceeds.

The impeller assembly includes a disc shaped base member 6 disposedadjacent the upper end of the casing and a shaft 5 suitably centrallyfixed to the base member 6 and extending upwardly therefrom. The shaft 5is arranged in suitably supported bearings disposed above and supportedby the casing. Shaft 5 is suitably coupled with a source of power, suchas an electric motor, not shown. Three forwardly curved angularly spacedblades 7 are fixed at one end thereof to the lower side of base member 6and extend axially downwardly therefrom. The other or free end of eachof the blades 7 includes a first portion 8 which extends outwardly ofthe inlet opening. The first portion 8 of each of the blades 7 extendsradially from the inner edge of the blade to adjacent the edge of theinlet opening. A second portion of the free end of each blade 7 is abovethe first portion 8 and extends radially to the outer edge of the blade.In addition, the second portion of the free end of each blade is closelyadjacent to the inner surface of the plate member 3. Thus, it might besaid that the free end of each blade 7 has a stepped shape.

The blades 7 are arranged with respect to each other without any hub.Instead, the inner edges of the blades 7 are radially spaced from theaxis of rotation of the impeller and are free rather than being securedto a hub. The blades 7 are thus arranged to define a central pocket, soto speak. As shown in the drawings the inner edge of each blade 7diverges from the fixed end to the free end thereof with respect to theaxis of rotation of the impeller.

With the pump 1 arranged in a storage tank, the material therein will bedrawn itno the inlet opening and discharged for recirculation within thetank or out of the tank as desired. The action of the blades 7 on softsolid matter will tend to break it into finer pieces until a smoothslurry is produced. Any large mass of solid material, such as a mat ofstraw, for example, will be acted upon by the first portions 8 of theblades 7 and will be broken apart without clogging the inlet opening. Asmall mass of breakable material will be drawn into the pocket betweenthe blades and then thrown out radially into the casing for discharge.These breakable masses will break apart into small pieces by thiscentrifugal action. A small mass of unbreakable material, such as astone, for example, will also be drawn into the pocket between theblades and, although it will not break apart, it will be thrown outradially for discharging and will not remain in the casing to jam theimpeller. Any fibrous material such as straw or rope will be carried bythe blades around the edge of the inlet opening and then will lodge inone of the slots 9 where the second portion of the free end of the bladewill cut olf the part of the material in the casing and throw it intothe casing for discharge.

It should be noted that the first portion 8 of each blade 7 shouldextend outwardly of the casing enough to act on material to break itapart. In addition, the first portions 8 should be made wide enough forstrength purposes, that is, sufficiently strong to break apart material.

It is also noted that the slots 9 can be varied in number as well asshape. The centrifugal force imparted to the fibrous material will causethe material to be urged into any shaped slot extending radially fromthe edge of the inlet opening.

It should now be appreciated how the advantages of my present inventionas set out in the introductory portion of this description are realized.It should also be apparent that the pump of my present invention isconsiderably simpler in construction, requiring less parts, than theslurry handling pumps used heretofore.

While I have illustrated and described a present preferred embodiment ofmy invention, it is to be understood that I do not limit myself thereto,and that my invention may be otherwise variously practiced within thescope of the following claims.

I claim:

1. A slurry handling pump, comprising:

a hollow scroll casing having an axial inlet opening means at one endthereof and a tangential discharge opening means through the side wallthereof; and

centrifugal impeller means sapported by said casing for rotationrelative thereto; said impeller means including a disc shaped basemember ahjacent the other end of said casing, a plurality of axiallyextending, angularly spaced blades defining a center axial pocket, eachof which blades having one end fixed to said base member and theopposite other end having a first portion with a free outer edgeextending outwardly beyond said inlet opening means and cooperatingtherewith to communite slurry and a second portion within said casingand having a free edge adjacent the inner surface of said one end ofsaid casing and forming the main blade pumping portion.

2. A slurry handling pump as set forth in claim 1 wherein said inletopening includes at least one radially extending slot.

3. A slurry handling pump as claimed in claim 1 wherein said blades areradially spaced from the axis of rotation of said impeller means.

4. A slurry handling pump as set forth in claim 1 Wherein said inletopening means includes a plate member removably attached to said one endof said casing; said plate member having a central opening generallycoaxial with the axis of rotation of said impeller means correspondingsubstantially said inlet opening means, and also having at least oneslot extending radially from the edge of said central opening.

5. A slurry handling pump as set forth in claim 4 wherein the innersurface of said plate member is substantially flush with the innersurface of said one end of said casing; said first portion of each ofsaid blades extends radially to adjacent the edge of said centralopening; and said second portion extends radially outwardly from saidfirst portion and is adjacent the inner surface of said plate member.

6. A slurry handling pump, comprising:

a hollow scroll casing having an axial opening through one end thereofand a tangential discharge opening through the side wall thereof;

a plate member removably fixed to said one end of said casing and havingan inner surface substantially flush with the inner surface of said oneend, and also having a central opening substantially coaxial with saidaxial opening; said plate member further having at least one slotextending radially from the edge of said central opening;

centrifugal impeller means supported by said casing for rotationrelative thereto; said impeller means including a disc shaped basemember disposed adjacent the other end of said casing, a shaft fixedcentrally on said disc member and extending outwardly from said otherend of said casing, a plurality of angularly blades fixed to said basemember and extending axially therefrom toward said one end of saidcasing;

each of said blades having an upper end fixed to said base member, alower end opposite the upper end, an inner edge towards the axis ofrotation of the impeller means, and an outer edge away from the axis ofrotation of the impeller means;

said lower end of each of said blades having a stepped shape including afirst portion adjacent said inner edge and disposed axially outwardly ofsaid plate member and extending radially to adjacent the edge of saidcentral opening in said plate member, and a second portion extendingfrom said outer edge to adjacent the edge of said central opening andlying above said first portion adjacent the inner surface of said platemember; and

said inner edge of each of said blades having a diverging shape fromsaid upper end toward said lower end with respect to the axis ofrotation of said impeller means.

(References on following page) References Cited UNITED STATES PATENTSCleveland 415-205 Hargis 103115 Minnard 4152l3 Forrest 415213 Smith103111 Beehler et a1 230-127 Blum 4152l3 Nelsen 24155 Stoner et a1103115 6 3,162,135 12/1964 NiChOlSfltfil 103 115 3,253,357 5/1966 Allard103 111 FOREIGN PATENTS 960,112 10/1949 France 415 125 5 1,377,1859/1964 France 415-121 HENRY F. RADUAZO, Primary Examiner UNITED STATESPATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 560 106 DatedFebruary 2 1971 Nils-Johan Sahlstrom Inventor(s) It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1 line 11 "scrool" should read scroll line 52 "other" should readothers line 59 "bades" should read blades Column 3 line 28 "itno" shouldread into Column 4 line 3 "ahjacent" should read adjacent lines 53 and54 after "angularly" insert spaced Signed and sealed this 29th day ofJune 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR Attesting OfficerCommissioner of Patents

